A Nuts and Bolts Dichotomous Key Example:
The following are all made of steel, and are all found in the toolbox. Use the dichotomous key
below to correctly identify the “species” of metal that they are.
1a. With a hole
Go to Question 2
1b. Without a hole
Go to Question 3
2a. Six sided
It is Species #1
2b. Four sided
It is Species #6
Go to Question 4
3a. With threading
3b. Without threading
4a. Pointy tip
It is Species #8
Go to Question 5
4b. No pointy tip
Go to Question 6
5a. Rounded head
It is Species #4
5b. Not rounded head
6a. Flat head
It is Species #7
Go to Question 7
6b. Not flat head
It is Species #2
7a. Body length twice the width of head
It is Species #5
7b. Body length not twice the width of head It is Species #3
The identifying numbers have been removed from the nuts and bolts in the following picture.
Use the key to identify them and write the correct species number in the blank next to each one.
Answer Key:
#6
#4
#8
#2
#5
#7
#3
#1